I am so sorry this happened to you. I am one who also gets the letter about dense ribrous breasts and usually have a 6 moth mamo. I had my first biopsy in my early 20s. I,m 66 now but can remember this because i used to laugh at how my insurance wouldn't cover my left breast because of the biopsy. Luckly that is illegal now. My ILC was accidently found. They found a suspicious area on my rt breast and ordered an ultrasound that showed nothing so they ordered a MRI. The MRI showed the cancer in my left breast and the right suspicious area was calcifications. I am so lucky. It was small and slow growing. I was coaxed into a lumpectomy even though I wanted a DMX. At the time my MRI showed areas of concern again, so I sought out another facility to do the DMX. I didn't want to go through radiation because of the side effects. Six months after the lumpectomy I had the DMX and the biopsy found ILC in situ in my left breast and numerous areas of precancer in both breasts. I am so happy I went with my gut and fought for what I wanted. On a side note, prior to my lumpectomy I was talking with my insurance company regarding a different claim. I mentioned that "now I came down with breast cancer". He was so nice. He asked if he could talk to me as though I were his sister. Of course he could. He said I should get a double masectomy and ask for a PET scan. He has been in the business over 20 years and he either had personal experience with ILC or professional experience. I am so thankful to him because I may not have fought as hard for the DMX and who knows when the ILC in situ would have popped our and not been found by a mamogram until it was too late. Two oncologists said a yearly mamogram would have been my yearly followup. I interviewed 3 oncologists before I found one I trusted. And I am also so thankful for the radiologist who had me do all the tests that eventually found the sneaky ILC. Just remember we have to go with out gut and go elsewhere if we feel we are not getting the answers we want.